Microphone

Abstract

The utility model relates to a microphone, which comprises a packaging shell with an inner cavity, a sound hole for sound to flow into the inner cavity is arranged on the packaging shell, a vibrating diaphragm is arranged in the inner cavity, and the vibrating diaphragm divides the inner cavity into a front cavity close to one side of the sound hole and a rear cavity far away from one side of the sound hole; a breathable barrier piece is arranged in the rear cavity, the Gurley breathable resistance of the breathable barrier piece is smaller than 10 s, the thickness is smaller than 80 microns, and the maximum aperture is smaller than 50 microns; a separation cavity is defined by the breathable blocking piece and the inner wall of the rear cavity or is formed in the breathable blocking piece, and the separation cavity is filled with a porous material piece. According to the microphone, the volume of the rear cavity can be virtually enlarged, the sensitivity and the signal-to-noise ratio of the microphone are effectively improved, the performance of the microphone is improved, and the influence of falling powder on the vibrating diaphragm can be effectively reduced.

Description

Technical Field

[0001] The utility model relates to the field of audio, and particularly to a microphone. Background Art

[0002] A capacitive microphone is a device that converts sound signals into electrical signals. It utilizes the principle of a capacitor to sense the changes in sound waves. Capacitive microphones have a very flat frequency response and high sensitivity, so they are usually used in professional audio applications such as recording studios, live performances, and measurements.

[0003] Currently, due to the relatively compact packaging space of capacitive microphones on the market, the volume of the rear cavity of the microphone is small, which in turn results in a low signal-to-noise ratio of the microphone, seriously affecting the performance of the microphone. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a microphone that can virtually expand the volume of the rear cavity, effectively improve the sensitivity and signal-to-noise ratio of the microphone, enhance the performance of the microphone, and also effectively reduce the impact of powder deposition on the diaphragm.

[0005] The purpose of the utility model is achieved as follows: A microphone includes a packaging shell with an inner cavity. A sound hole for sound to flow into the inner cavity is provided on the packaging shell. A diaphragm is arranged in the inner cavity, and the diaphragm divides the inner cavity into a front cavity close to the sound hole side and a rear cavity far from the sound hole side. A breathable barrier is arranged in the rear cavity. The Gurley air permeability resistance of the breathable barrier is less than 10 s, the thickness is less than 80 μm, and the maximum pore diameter is less than 50 μm. A separation cavity is formed by the enclosure of the breathable barrier and the inner wall of the rear cavity or a separation cavity is formed inside the breathable barrier, and a porous material part is filled in the separation cavity.

[0006] In a preferred embodiment of the utility model, the material of the breathable barrier is polypropylene, polyethylene terephthalate, or polyimide. The Gurley air permeability resistance of the breathable barrier is less than 4 s, the thickness is less than 50 μm, and the maximum pore diameter is less than 20 μm.

[0007] In a preferred embodiment of the utility model, the breathable barrier is a breathable membrane. The breathable membrane is sleeved on a support ring, and the support ring sleeved with the breathable membrane is clamped on the inner wall of the rear cavity; alternatively, the breathable membrane is adhesively fixed on the inner wall of the rear cavity.

[0008] In a preferred embodiment of the utility model, the breathable barrier is a breathable membrane. The breathable membrane is sleeved on a porous sheet, and the porous sheet sleeved with the breathable membrane is clamped on the inner wall of the rear cavity; alternatively, a porous sheet is clamped on the inner wall of the rear cavity, the porous sheet and the inner wall of the rear cavity enclose a separation cavity, and the breathable membrane is adhered to the surface of the separation cavity opposite to the porous sheet.

[0009] In a preferred embodiment of the present utility model, the density of the porous sheet is 0.1-0.5 g / m 3 , and the thickness is 0.2-3 mm.

[0010] In a preferred embodiment of the present utility model, the air-permeable barrier is an air-permeable membrane, the air-permeable membrane is wrapped around the outer periphery of the porous material piece, and a separation cavity is formed by enclosing the inner wall of the air-permeable membrane.

[0011] In a preferred embodiment of the present utility model, the microphone is a capacitive microphone, and the porous material piece includes porous particles, porous powder, porous sheet and / or porous block.

[0012] In a preferred embodiment of the present utility model, the encapsulation housing includes a substrate and a housing provided on the substrate, and the substrate and the housing enclose to form an inner cavity; a substrate and an ASIC chip are provided on the substrate and located in the inner cavity, a diaphragm and a back plate are provided on the substrate, and an air gap is provided between the diaphragm and the back plate.

[0013] In a preferred embodiment of the present utility model, the sound hole is opened on the housing, and the closed space formed by the diaphragm, the substrate and the substrate constitutes the rear cavity, and the space formed by the diaphragm, the substrate, the substrate and the housing constitutes the front cavity.

[0014] In a preferred embodiment of the present utility model, the sound hole is opened on the substrate and corresponds to the position of the diaphragm, the space formed by the diaphragm, the substrate and the substrate constitutes the front cavity, and the closed space formed by the diaphragm, the substrate, the substrate and the housing constitutes the rear cavity.

[0015] In a preferred embodiment of the present utility model, the encapsulation housing includes a first substrate and a second substrate provided on the first substrate, and the first substrate and the second substrate enclose to form an inner cavity; a substrate and an ASIC chip are provided on the first substrate and located in the inner cavity, a diaphragm and a back plate are provided on the substrate, and an air gap is provided between the diaphragm and the back plate; the sound hole is opened on the first substrate and corresponds to the position of the diaphragm, the space formed by the diaphragm, the substrate and the first substrate constitutes the front cavity, and the closed space formed by the diaphragm, the substrate, the first substrate and the second substrate constitutes the rear cavity.

[0016] In a preferred embodiment of the present utility model, the encapsulation housing includes a circuit board and a housing provided on the circuit board, and the circuit board and the housing enclose to form an inner cavity; pads are provided on the outer wall of the circuit board, and a field effect transistor is provided on the circuit board and located in the inner cavity; an installation opening is opened on the housing, and a diaphragm and a back plate are arranged at intervals inside and outside along the axis of the installation opening in the installation opening, an air gap is provided between the diaphragm and the back plate, and a through hole is opened on the back plate and constitutes the sound hole; the space enclosed by the diaphragm, the inner wall of the installation opening and the back plate constitutes the front cavity, and the space formed by the diaphragm, the housing and the circuit board constitutes the rear cavity.

[0017] As described above, for the microphone of the present utility model, by providing a breathable barrier in the rear cavity of the microphone, either by enclosing the breathable barrier with the inner wall of the rear cavity or by forming a cavity inside the breathable barrier itself, a partition cavity is separated from the rear cavity. A porous material member is provided in the partition cavity. In a miniaturized microphone assembly, the acoustic effect of a large cavity is achieved, which can effectively improve the sensitivity of the microphone and increase the signal-to-noise ratio of the microphone. At the same time, the breathable barrier has a high breathability, enabling sufficient gas exchange and further improving the acoustic effect; the breathable barrier itself is thin and small in volume, which is more conducive to filling more materials; the breathable barrier can also effectively prevent the possibility of the porous material falling onto the diaphragm, effectively reducing the impact of powder falling on the diaphragm. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The following drawings are only intended to illustrate and explain the present utility model schematically and do not limit the scope of the present utility model. Among them:

[0019] Figure 1 : is a schematic structural diagram of the microphone provided by the present utility model.

[0020] Figure 2 : is another schematic structural diagram of the microphone provided by the present utility model.

[0021] Figure 3 : is another schematic structural diagram of the microphone provided by the present utility model.

[0022] Figure 4 : is another schematic structural diagram of the microphone provided by the present utility model.

[0023] Description of the reference numerals in the drawings:

[0024] 1. Encapsulation housing; 11. Sound hole; 12. Front cavity; 13. Rear cavity; 131. Breathable barrier; 14. Substrate; 15. Outer shell; 151. Mounting opening; 16. First substrate; 17. Second substrate; 18. Circuit board; 19. Solder pad;

[0025] 2. Porous material member;

[0026] 3. Substrate;

[0027] 4. Diaphragm;

[0028] 5. Backplate;

[0029] 6. ASIC chip;

[0030] 7. Field effect transistor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] In order to have a clearer understanding of the technical features, objectives, and effects of the present utility model, the specific embodiments of the present utility model will now be described with reference to the accompanying drawings.

[0032] As Figures 1 to 4 shown, the present utility model provides a microphone, which includes a packaging housing 1 having an inner cavity. A sound hole 11 for sound to flow into the inner cavity is opened on the packaging housing 1. A diaphragm 4 is arranged in the inner cavity. The diaphragm 4 divides the inner cavity into a front cavity 12 on the side close to the sound hole 11 and a rear cavity 13 on the side far from the sound hole 11. A breathable barrier 131 is arranged in the rear cavity 13. The Gurley-air permeability of the breathable barrier 131 is less than 10 s, the thickness is less than 80 μm, and the maximum pore diameter is less than 50 μm. The breathable barrier 131 and the inner wall of the rear cavity 13 enclose a separation cavity, or a separation cavity is formed inside the breathable barrier 131. A porous material member 2 is filled in the separation cavity.

[0033] Therefore, in the microphone of the present utility model, by arranging the breathable barrier 131 in the rear cavity 13 of the microphone, in the way that the breathable barrier 131 and the inner wall of the rear cavity 13 enclose a cavity or a cavity is formed inside the breathable barrier 131 itself, the rear cavity 13 is divided into a separation cavity. The porous material member 2 is arranged in the separation cavity. In a miniaturized microphone assembly, the acoustic effect of a large cavity is achieved, the sensitivity of the microphone can be effectively improved, and the signal-to-noise ratio of the microphone can be improved. At the same time, the breathable barrier 131 has high air permeability, can fully perform gas exchange, and further improves the acoustic effect. The breathable barrier 131 itself is thin and small in volume, which is more conducive to filling more materials. The breathable barrier 131 can also effectively prevent the possibility of the porous material falling onto the diaphragm 4, and effectively reduce the influence of powder falling on the diaphragm 4 during vibration.

[0034] The above-mentioned porous material member 2 can be a combination of one or more of porous particles, porous powders, porous sheets, porous blocks, etc. When the porous material member 2 adopts a sheet structure or a block structure, the signal-to-noise ratio and sensitivity of the microphone are higher than those when using porous particles or porous powders.

[0035] Further preferably, the Gurley-air permeability of the breathable barrier 131 is less than 4 s, the thickness is less than 50 μm, and the maximum pore diameter is less than 20 μm. Even more preferably, the Gurley-air permeability of the breathable barrier 131 is less than 1 s, the thickness is less than 30 μm, and the maximum pore diameter is less than 10 μm. Under these parameters, the breathable barrier 131 is thinner and lighter, and can fill more materials. The material of the above-mentioned breathable barrier 131 is preferably polypropylene (PP), polyethylene terephthalate (PET) or polyimide (PI).

[0036] The porous material component 2 contains a porous material, which is a combination of one or more of zeolite, activated carbon, MOF, COF, aerogel, hydrogel, etc. Zeolite is preferably included in the porous material component 2. When using zeolite, the corresponding signal-to-noise ratio and sensitivity are better than those when using activated carbon. Zeolite material has good air absorption and release ability, can virtually expand the volume of the rear cavity 13, and better improve the performance of the microphone. In some embodiments, the form of the porous material component 2 is powder, and the size of the powder is 50 - 300 nm. In some embodiments, the form of the porous material component 2 is particles, and the size of the particles is 10 - 300 μm. In some embodiments, the form of the porous material component 2 is a sheet, with a density of 0.1 - 0.5 g / m 3 , and the thickness is 0.1 - 1 mm. In some embodiments, the form of the porous material component 2 is a block, with a density of 0.1 - 0.5 g / m 3 , and the thickness is 1 - 3 mm.

[0037] In some embodiments, the air-permeable barrier 131 is fixed on the inner wall of the rear cavity 13. The air-permeable barrier 131 can be a combination of one or more of rigid PET mesh and air-permeable film, etc. The air-permeable barrier 131 is more preferably an air-permeable film, which has better powder leakage prevention performance and can ensure the long-term stable operation of the MEMS. In some embodiments, the air-permeable barrier 131 of the rigid PET mesh is clamped in the grooves, buckles, etc. inside the corresponding housing of the rear cavity 13.

[0038] In some embodiments, the air-permeable barrier 131 is an air-permeable film and is sleeved on a support ring (such as a plastic ring or a metal ring), and the support ring sleeved with the air-permeable barrier 131 is clamped on the card slot on the inner wall of the rear cavity 13; alternatively, the air-permeable barrier 131 is adhesively fixed on the inner wall of the rear cavity 13 by an adhesive or double-sided tape.

[0039] In some embodiments, the air-permeable barrier 131 is an air-permeable film and is sleeved on a porous sheet, and the porous sheet sleeved with the air-permeable barrier 131 is clamped on the card slot on the inner wall of the rear cavity 13; alternatively, a porous sheet is clamped in the card slot on the inner wall of the rear cavity 13, and the porous sheet and the inner wall of the rear cavity 13 enclose the above-mentioned partition cavity, and the air-permeable barrier 131 is heated and softened and adhered to the surface of the partition cavity opposite to the porous sheet.

[0040] In this embodiment, the material of the porous sheet is a porous material and has a certain air permeability. The density of the porous sheet is preferably 0.1 - 0.5 g / m 3, the thickness is preferably 0.2 - 3 mm. By providing the porous sheet, it can support the air-permeable barrier 131, and further reduce the possibility of the porous material falling onto the diaphragm 4, more effectively reducing the influence of powder falling on the diaphragm 4. Especially for MEMS microphones, the diaphragm 4 is small in volume, and the influence of powder falling on it is great. In this embodiment, the cooperation of the air-permeable barrier 131 and the porous sheet can well avoid this influence.

[0041] In some embodiments, the air-permeable barrier 131 is an air-permeable film, which wraps the porous material member 2 and is assembled in the rear cavity 13. For example, the air-permeable film after wrapping the porous material member 2 can be placed inside the rear cavity 13, clamped in the card slot on the inner wall of the rear cavity 13, or adhered to the inner wall of the rear cavity 13.

[0042] To better illustrate the effects of the microphone of the present invention, taking the structure of a MEMS microphone as an example, several specific embodiments with the above-mentioned air-permeable barrier 131 and porous material member 2 provided in the rear cavity 13 and a blank comparative example without the air-permeable barrier 131 and porous material member 2 are respectively tested for signal-to-noise ratio and sensitivity for further comparative illustration, as follows:

[0043] Example 1

[0044] The air-permeable barrier 131 is a rigid PET mesh (Gurley air permeability resistance is 0.2 s, thickness is 40 μm, maximum pore size is 10 μm), which is clamped in the groove inside the corresponding housing of the rear cavity 13, and forms a closed partition cavity with the inner wall of the corresponding housing of the rear cavity 13. The volume of this partition cavity is 0.001 CC. 0.001 CC of porous particles are filled in this partition cavity, and the average diameter of the porous particles is 50 μm.

[0045] Example 2

[0046] The air-permeable barrier 131 is an air-permeable film (Gurley air permeability resistance is 3.5 s, thickness is 45 μm, maximum pore size is 10 nm), which is sleeved on a support metal ring and clamped in the groove on the inner wall of the rear cavity 13, and forms a closed partition cavity with the inner wall of the corresponding housing of the rear cavity 13. The volume of this partition cavity is 0.001 CC. 0.001 CC of porous powder is filled in this partition cavity, and the average diameter of the porous powder is 15 nm.

[0047] Example 3

[0048] The air-permeable barrier 131 is an air-permeable film (the parameters of the air-permeable film are the same as those in Example 2). A porous sheet is clamped in the card slot on the inner wall of the rear cavity 13. The porous sheet and the inner wall of the rear cavity 13 enclose the above-mentioned partition cavity. The air-permeable barrier 131 is heated and softened and adhered to the surface of the partition cavity opposite to the porous sheet. The porous sheet contains zeolite, binder and fiber, and the density is 0.2 g / m3 , with a thickness of 0.1 mm. 0.001 CC of porous particles with an average diameter of 50 μm are filled in the separation cavity.

[0049] Example 4

[0050] The air-permeable barrier 131 is an air-permeable membrane (the parameters of the air-permeable membrane are the same as those in Example 2). A porous sheet is clamped in the card slot on the inner wall of the rear cavity 13. The porous sheet and the inner wall of the rear cavity 13 enclose the above-mentioned separation cavity, and the air-permeable barrier 131 is heated and softened and adhered to the surface of the separation cavity opposite to the porous sheet. The porous sheet contains zeolite, binder and fiber, and the density is 0.2 g / m 3 , with a thickness of 0.1 mm. The volume of the separation cavity is 0.001 CC. 0.001 CC of porous powder with an average diameter of 15 nm is filled in the separation cavity.

[0051] Example 5

[0052] The air-permeable barrier 131 is an air-permeable membrane (the parameters of the air-permeable membrane are the same as those in Example 2), wraps the porous powder, and is pasted in the rear cavity 13 with an adhesive. The bulk volume of the powder is 0.001 CC, and the average diameter is 15 nm.

[0053] Example 6

[0054] The air-permeable barrier 131 is an air-permeable membrane (the parameters of the air-permeable membrane are the same as those in Example 2), wraps the porous sheet body, and is pasted in the rear cavity 13 with an adhesive. The porous sheet body contains zeolite, binder and fiber, and the density is 0.2 g / m 3 , with a thickness of 0.1 mm.

[0055] Blank control

[0056] A silicon microphone module without the air-permeable barrier 131 and the porous material part 2, such as the 3722 MEMS silicon microphone of Zhiyuan Audio Technology.

[0057] Test the signal-to-noise ratio and sensitivity of the microphones corresponding to the blank control and the foregoing Examples 1-6. The test results are shown in Table 1 below:

[0058] Table 1

[0059]

[0060] It can be seen from the test results in the above table that by setting the air-permeable barrier 131 in the rear cavity 13 of the microphone to separate a separation cavity in the rear cavity 13 and setting the porous material part 2 in the separation cavity, the sensitivity and signal-to-noise ratio of the microphone can be effectively improved. In addition, the signal-to-noise ratio is higher when the air-permeable barrier 131 uses an air-permeable membrane than when using a mesh cloth.

[0061] In some embodiments, the microphone is a capacitive microphone. Generally, a microphone mainly includes a diaphragm 4, a backplate 5, a capacitor, an output terminal, and a package housing 1. The diaphragm 4 is usually made of a very thin metal or plastic material, and it is responsible for sensing sound waves and converting them into mechanical vibrations. The backplate 5 is located opposite the diaphragm 4, is usually made of metal, and forms two electrodes of a capacitor with the diaphragm 4; Sound waves cause the vibration of the diaphragm 4, thereby changing the distance between the diaphragm 4 and the backplate 5, and this change in distance is the change in the capacitance of the capacitor. The space between the diaphragm 4 and the backplate 5 constitutes a capacitor. When sound waves act on the diaphragm 4, the distance between the diaphragm 4 and the backplate 5 changes, resulting in a change in the capacitance value of the capacitor. The output terminal is where the electrical signal of the microphone is output and can be connected to an amplifier or other audio devices. The package housing 1 is located on the outermost layer of the microphone, used to protect the internal structure from damage while allowing sound to pass through.

[0062] In this embodiment, according to the different structures of the package housing 1 and the different positions of the sound holes 11, there can be the following several structural forms.

[0063] In one embodiment, the package housing 1 includes a substrate 14 and a housing 15 provided on the substrate 14, and the substrate 14 and the housing 15 enclose an inner cavity; A substrate 3 and an ASIC chip 6 are provided on the substrate 14 and located in the inner cavity, and a diaphragm 4 and a backplate 5 are provided on the substrate 3, and there is an air gap between the diaphragm 4 and the backplate 5.

[0064] In this embodiment, the sound holes 11 can be opened on the housing 15 or on the substrate 14. When the sound holes 11 are opened on the housing 15, referring to Figure 1 , the enclosed space formed by the diaphragm 4, the substrate 3, and the substrate 14 constitutes the rear cavity 13, and the space formed by the diaphragm 4, the substrate 3, the substrate 14, and the housing 15 constitutes the front cavity 12. When the sound holes 11 are opened on the substrate 14, the sound holes 11 correspond to the position of the diaphragm 4 so that sound waves can reach the diaphragm 4, referring to Figure 2 , the space formed by the diaphragm 4, the substrate 3, and the substrate 14 constitutes the front cavity 12, and the enclosed space formed by the diaphragm 4, the substrate 3, the substrate 14, and the housing 15 constitutes the rear cavity 13.

[0065] In another embodiment, the difference from Figure 1 and Figure 2 is that it is a multi-layer substrate structure and does not contain the housing 15, and the microphone device (substrate 3, ASIC chip 6, diaphragm 4, and backplate 5) is arranged in the enclosed space of the multi-layer substrate. Specifically, referring to Figure 3, the encapsulation housing 1 includes a first substrate 16 and a second substrate 17 provided on the first substrate 16. The first substrate 16 and the second substrate 17 enclose to form an inner cavity; a substrate 3 and an ASIC chip 6 are provided on the first substrate 16 and within the inner cavity. A diaphragm 4 and a backplate 5 are provided on the substrate 3. An air gap is provided between the diaphragm 4 and the backplate 5; a sound hole 11 is opened on the first substrate 16 and corresponds to the position of the diaphragm 4. The space enclosed by the diaphragm 4, the substrate 3, and the first substrate 16 forms a front cavity 12, and the enclosed space formed by the diaphragm 4, the substrate 3, the first substrate 16, and the second substrate 17 forms a rear cavity 13.

[0066] It can be understood that Figures 1 to 3 the microphones shown all belong to MEMS microphones. In these two types of embodiments, the substrate 3, the diaphragm 4, and the backplate 5 form a MEMS chip. The MEMS chip is a transducer component that converts sound signals into electrical signals and is fabricated using MEMS (Micro-Electro-Mechanical System) technology; the ASIC (Application Specific Integrated Circuit) chip is a signal amplification device mainly used to amplify the electrical signals output by the MEMS chip for subsequent processing; the specific structures of the MEMS chip and the ASIC chip 6 are prior art. Figure 1 and Figure 2 the outer housing 15 in Figure 3 and the second substrate 17 in Figure 1 and Figure 2 the outer housing 15 and the substrate 14 are mounted together in Figure 3 and the second substrate 17 and the first substrate 16 are mounted together in

[0067] In yet another embodiment, referring to Figure 4, the encapsulation housing 1 includes a circuit board 18 and a housing 15 disposed on the circuit board 18. The circuit board 18 and the housing 15 enclose an inner cavity. A pad 19 is provided on the outer wall of the circuit board 18 (i.e., the side facing away from the housing 15), and a field effect transistor 7 is provided on the circuit board 18 and located in the inner cavity. An installation opening 151 is formed in the housing 15. A diaphragm 4 and a back plate 5 are arranged at intervals inside and outside along the axis of the installation opening 151 in the installation opening 151 (the plate surfaces of the diaphragm 4 and the back plate 5 are perpendicular to the axis of the installation opening 151, and the outer peripheries of the diaphragm 4 and the back plate 5 are connected to the inner wall of the installation opening 151). An air gap is provided between the diaphragm 4 and the back plate 5. A through hole is formed in the back plate 5 to form a sound hole 11. The diaphragm 4, the inner wall of the installation opening 151, and the back plate 5 enclose a front cavity 12, and the space enclosed by the diaphragm 4, the housing 15, and the circuit board 18 forms a rear cavity 13.

[0068] It can be understood that the housing 15 is a cavity structure with one end open, so as to Figure 4 mount the housing 15 and the circuit board 18 together to enclose the above-mentioned inner cavity. Figure 4 The microphone shown in

[0069] In some embodiments, the above-mentioned inner cavity is a sealed cavity.

[0070] In some embodiments, the above-mentioned inner cavity is not completely sealed. According to actual design requirements, the encapsulation housing 1 may be provided with ventilation holes of different sizes and shapes for different process purposes, such as filling of porous materials, sound leakage of the module, etc. It can be understood that the improvements made to the encapsulation housing 1 according to actual design requirements are also within the protection scope of the present invention.

[0071] The above is only a schematic specific embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present invention shall fall within the protection scope of the present invention.

Claims

1. A microphone, characterized in that, It includes a packaging shell with an inner cavity. An acoustic hole for sound to flow into the inner cavity is provided on the packaging shell. A diaphragm is arranged in the inner cavity, and the diaphragm divides the inner cavity into a front cavity close to the acoustic hole side and a rear cavity far from the acoustic hole side. A breathable barrier is arranged in the rear cavity. The Gurley air permeability resistance of the breathable barrier is less than 10 s, the thickness is less than 80 μm, and the maximum pore diameter is less than 50 μm. The breathable barrier and the inner wall of the rear cavity enclose a partition cavity, or a partition cavity is formed inside the breathable barrier, and a porous material piece is filled in the partition cavity.

2. The microphone according to claim 1, wherein the material of the breathable barrier is polypropylene, polyethylene terephthalate or polyimide; the Gurley air permeability resistance of the breathable barrier is less than 4 s, the thickness is less than 50 μm, and the maximum pore diameter is less than 20 μm.

3. The microphone according to claim 1, wherein the breathable barrier is a breathable film. The breathable film is sleeved on a support ring, and the support ring sleeved with the breathable film is clamped on the inner wall of the rear cavity; or, the breathable film is adhesively fixed on the inner wall of the rear cavity.

4. The microphone according to claim 1, wherein the breathable barrier is a breathable film. The breathable film is sleeved on a porous sheet, and the porous sheet sleeved with the breathable film is clamped on the inner wall of the rear cavity; or, a porous sheet is clamped on the inner wall of the rear cavity, and the porous sheet and the inner wall of the rear cavity enclose the partition cavity, and the breathable film is adhered to the surface of the porous sheet facing away from the partition cavity.

5. The microphone according to claim 4, wherein The density of the porous sheet is 0.1 - 0.5 g / m 3 , and the thickness is 0.2 - 3 mm.

6. The microphone according to claim 1, wherein the breathable barrier is a breathable film. The breathable film wraps around the outer periphery of the porous material piece, and the inner wall of the breathable film encloses the partition cavity.

7. The microphone according to claim 1, wherein the microphone is a capacitive microphone, and the porous material piece includes porous particles, porous powder, porous sheet and / or porous block.

8. The microphone according to claim 1, wherein the packaging shell includes a substrate and a housing arranged on the substrate. The substrate and the housing enclose to form the inner cavity; a substrate and an ASIC chip are arranged on the substrate and located in the inner cavity. A diaphragm and a back plate are arranged on the substrate. An air gap is arranged between the diaphragm and the back plate. The acoustic hole is opened on the housing. The closed space formed by the diaphragm, the substrate and the substrate constitutes the rear cavity, and the space formed by the diaphragm, the substrate, the substrate and the housing constitutes the front cavity; or the acoustic hole is opened on the substrate and corresponds to the position of the diaphragm. The space formed by the diaphragm, the substrate and the substrate constitutes the front cavity, and the closed space formed by the diaphragm, the substrate, the substrate and the housing constitutes the rear cavity.

9. The microphone according to claim 1, wherein The encapsulation housing includes a first substrate and a second substrate disposed on the first substrate. The first substrate and the second substrate enclose to form the inner cavity. A substrate and an ASIC chip are disposed on the first substrate and within the inner cavity. A diaphragm and a backplate are disposed on the substrate. An air gap is provided between the diaphragm and the backplate. The sound hole is formed in the first substrate and corresponds to the position of the diaphragm. The space enclosed by the diaphragm, the substrate, and the first substrate forms the front cavity. The enclosed space formed by the diaphragm, the substrate, the first substrate, and the second substrate forms the rear cavity.

10. The microphone according to claim 1, wherein The encapsulation housing includes a circuit board and a housing disposed on the circuit board. The circuit board and the housing enclose to form the inner cavity. A pad is provided on the outer wall of the circuit board, and a field effect transistor is disposed on the circuit board and within the inner cavity. An installation opening is formed in the housing. A diaphragm and a backplate are disposed in the installation opening at intervals inside and outside along the axis of the installation opening. An air gap is provided between the diaphragm and the backplate. A through hole is formed in the backplate and constitutes the sound hole. The space enclosed by the diaphragm, the inner wall of the installation opening, and the backplate forms the front cavity. The space enclosed by the diaphragm, the housing, and the circuit board forms the rear cavity.

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